/Engine/Source/Runtime/Engine/Classes/Engine/EngineTypes.h
Per-light settings for Lightmass
struct FLightmassLightSettings
bool
bUseAreaShadowsForStationaryLight
Whether to use area shadows for stationary light precomputed shadowmaps.
float
IndirectLightingSaturation
0 will be completely desaturated, 1 will be unchanged
float
ShadowExponent
Controls the falloff of shadow penumbras